Armature for dynamo-electric machines



(No ModeL) E. THOMSON.

ARMATURE FOR DYNAMO ELECTRIC MAGHINES.

N0. 400,973. Patented Apr. 9, 1889.

UNITED STATES PATENT OFFICE.

ELIIIU THOMSON, OF LYNN, l\ZIASSACHUSETTS.

ARMATURE FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 400,973, dated April 9, 1889.

Application filed October 15, 1888. Serial No. 288,162. (No model.)

To aZZ whom it may concern.-

Be it known that I, ELIHU THOMSON, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Armatures for Dynamos, of which the following is a specification.

My invention relates to the construction of ring-armatures for dynamo-electric machines or motors-that is to say, to the form of armature in which a ring-core like that of a Gramme machine is employed, having coils disposed upon the ring in such way that the circumferential axis of the ring passes through the center of the coils.

It has heretofore been proposed to construct ring-armatures in sections to facilitate the application of the coils; but the plans heretofore proposed require the use of cumbrous fastening devices, interfering with the disposition of the coils upon the core, and in many cases rendering itnecessary to employ a less number of coils than would be permitted in the case of a plain ring or hollow cylinder. In other cases the construction detracts from the amount of iron in the core,when such core is a laminated one, or interferes with the continuity of the magnetic circuit in the core, thus giving rise to irregularity of action in the machine.

The obj eet of my invention is to obtain a ring-armature in which the core may be a laminated structure, in which the magnetic circuit shall be almost perfectly closed, facilitate the work-of construction by permitting the coils to be formed and afterward placed on the core, to permit easy repair in case of damage to any part of the winding or its insulation, and to produce at the same time an armature structure which shall be symmetrical, free from unwieldy projections from its core, and in general easy and cheap of construction.

In constructing a ring-armature in accordance with my invention I proceed as follows: A laminated ring-core is constructed in any suitable way with a notch or gap in one side of sufficient width to permit the insertion or winding of the coils. The core may be made by piling pieces or washers of sheet-iron upon one another and clamping orbolting them together. Each ring piece or washer may be stamped out of sheet metal as a discontinuous ring--that is to say, a ring a portion of which is lacking atone side to form the notch or gap and a number of such pieces piled togetheror the complete cylinder may be formed of complete rings and the notch or gap afterward cut out. The cylinder or ring is generally formed with internal slots to receive the arms of a spider-frame carried by the shaft of the machine. The ring-core may be covered, before placing the coils thereon, with a heavy layer or coating of insulating material to prevent the coils from making contact with the core, and the plates of which the core is built up may be insulated from one anotherby paper or a thin layer of other insulating material. The coils, preferably wound previously upon a suitable form, are now applied through the notch or gap, and aftera sufficient number have been applied the narrow section or notch is filled up with a plug or bundle of sheet-iron pieces, either the same or in every practical respect equivalent to those which have been removed to form the notch, or of a size to exactly fill the space left in the rings or washers from which the core is built up. Such bundle or plug is forced tightly or snugly into place, and is so constructed and applied that when in place its laminee shall lie in planes parallel to those of the remainder of the core, so that in effect there shall be in the completed structure acomplete magnetic ring-circuit formed by each plate. The coils are now disposed with reference to the spider in the position which they shall finally occupy, one or more of them occupying a position over or lapping upon the plug, and the core is then applied to the spider-frame. Before or after this operation binding-rings or wire wound over the coils are applied to keep the plug or bundle in place, or other devices are applied to secure the same in place.

Having described the general nature of my invention, I will proceed to describe the same more particularly by referring .at the same time to the accompanying drawings, in which Figure 1 shows an isometric projection of the core without any winding upon it and without any shaft shown or spider-support therefor. Fig. 2 illustrates the manner of placing the windingon the core. Fi 3 shows the manner of filling the gap in the core which has been left for the insertion of the wind ing. Fig.4 is a view of the armature complete as it appears when constructed and tinished, with the coils placed thereon and with the outside binding which holds the coils and plug or bundle down.

In Fig. l, A A is the body of the armature complete, built up of rings, with a notch or gap cut into it for the insertion of the plug \V. The rings or washers A A have, as usual, notches inside for stringing them upon the coring spider or support, and are bolted together or held in place with respect to each other in any suitable way common to the art. Each ring, however, is notched at one side, with a narrow notch or intersection out therefrom. This enables the coils C, which are to be slipped over the ring, Fig. 2, to be put through the slot and then carried around the ring to the desired position, coil after coil being thus added until the desired number has been strung upon the ring-core. After this has been done the plug or bundle of pieces IV, Fig. 3, which are preferably bolted together by being strung upon an insulated bolt, is inserted and forced into place by the exertion of considerable pressure, the fit being tight enough to require a considerable amount of mechanical force to bring the piece or plug \V down into position. As will be seen, the laminze of the plug abut with their ends against the ends of the laminae of the body of the core, the latter having their magnetic circuits separately closed by the lamina; of the plug.

The sides of the notch or slit can be either slightly tapered, or, preferably, quite parallel, so that if the plug V has been once inserted with great pressure it is not easily removed, even by the revolution of the whole structure at a high rate of speed.

In Fig. 3 the internal notches, n n n n, are shown by which the whole structure is afterward supported, and the notch or gap in the rings A A is indicated at g. After the placing of the coils and the insertion of the plug the distribution of the coils may be made, the

carrying support or spider H, Fig. 4, inserted into the notches for carrying the structure upon the shaft, and the outside binding, B B, of wire applied over the coils which have been placed on the armature. This binding is put on sufficiently tight and bears down upon the coils to give an additional security in holding the plug \V in place. If not firmly secured, the tendencyduring revolution being outward, it might gradually work out; but the binding being tightly applied will act as an effective check upon such movement. Other means might, however, be employed for holding the plug in place.

What I claim as my invention is- 1. In a ring-armature for dynamo-electric machines or motors, a laminated core having a notch or gap at one side for the insertion of the coils closed magnetically by a laminated plug or bundle fitted tightly into the notch or gap to complete or restore the magnetic circuit after application of the coils, in combination with suitable fastening devices for holding said plug against displacement by revolution of the armature.

2. In a ring-armature, a laminated ring-core having a notch or gap at one side filled by a laminated plug fitted tightly therein with the ends of its laminre abutting against and closing the magnetic circuits for the laminae of the body of the core, in combination with coils applied over said plug, and binding-rings of wire for holding the coils and plug in place.

3. I11 a ring-armature, a laminated ring-core having a gap or notch at one side closed by a tightly-fitting plug or bundle of plates abutting against the ends of the plates of the body of the core, so as to close the magnetic circuits of the latter and form practically a uniform continuous laminated ring-armature, as and for the purpose described.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 10th day of October, A. D. 1888.

ELIHU THOMSON. itn esses:

MERLE J. WIGHTMAN, J. W. GIBBONEY. 

